Thanks , will try replacing the TDA 2222 and if that doesn't work them will use the LM386 amp
For scratchy audio on a V3, could be in the TDA2822 amp.
An easy way to check this is to take the VOL-M wire from the volume control pot,
detach that wire from the TDA2822 pin 7, then connect that wire plus a ground up
to some other audio amplifer.? This could be the auxiliary input of a hifi stereo,
or it could be an LM386 module such as this:?
? ??
If that sounds good, then the problem is in the TDA2822 stage.
We did have some trouble with the "WX" version of the TDA2822 blowing up:
? ??/g/BITX20/message/64247?p=,,,20,0,0,0::Created,,tda2822+ke7er,20,2,0,29417614
The TDA2822's marked "FCI" pretty much all did fine.
I don't recall reports of bad audio on the TDA2822's, other than no audio after they blew up.
The v4 uBitx with the discrete transistor audio amp did have scratchy audio due to crossover distortion,
if you have a v4 then replacing that part of the circuit with an LM386 module as described above is a good solution.
?
It is possible that your bad audio is in the pre-amp at Q70, or in the demodulator.
But I would try replacing the TDA2822 stage as described above first.
Jerry, KE7ER
On Tue, Nov 3, 2020 at 09:52 AM, rajesh huddar wrote:
The audio is very scratchy on my Ubitx V3.
What needs to be done.
rajesh huddar